Method of and means for producing dense articles from molten materials



30, 1 6 s. R. MORTON METHOD OF AND MEANS FOR PRODUCING DENSE ARTICLESFROM MOLTEN MATERIALS Filed Sept 8, 1964 United States Patent 3,268,960METHOD OF AND MEANS FOR PRODUCING DENSE ARTICLES FRGM MGLTEN MATERIALSGlenn R. Morton, 7025 Sarpy Ave, Omaha, Nebr.

' Filed Sept. 8, 1964, Ser. No. 395,983

2 Claims. (Cl. 2268) This is a continuation-impart application of myappli cation entitled Method of and Means for Producing Dense ArticlesFrom Molten Materials, Serial No. 51,903, under the filing date ofAugust 25 1960, now abandoned.

This invention relates to the method of and means for producing articlesfrom molten materials and more particularly to equipment which willcompress the molten material into a dense product during its coolingphase.

Both metal and plastic mold casting is old. Also the forging of materialinto articles is old. In general, forgings are compressed and have densecharacteristics while many castings are objectionable porous incharacter. However, many manufactured items must he produced byinjecting into a casting mold cavity a quantity of molten material orlike. The relatively recent method of vacuum die casting has contributedmuch to the art but even by the employment of this method many castingsare unsatisfactory. Much of this trouble has been experienced if a partof the casting is relatively large in mass and other parts are small inthickness such as protruding flanges 01' like. The reason for this isthat the smaller extensions of the casting cool and harden first andwhile the core of the larger portion is still molten. As the core of thelarger mass cools and hardens it obviously shrinks in size therebypulling on and affecting the smaller portions. Obviously this resultsnot only in imperfect castings but castings that may well beobjectionable porous and without the necessary strength to function forthe uses intended.

Therefore, one of the principal objects of my invention is to provide amethod of and means for producing a closely knit dense castingregardless of its shape or size.

More specifically the object of this invention is to provide castingequipment wherein at least one face of the mold moves toward the otherafter the injection of the molten material into the mold cavity and withthe further step that even after the movable face of the mold hascompleted its forward movement, pressure will still be exerted on thecasting material until it has congealed and solidified.

A further object of this invention is to provide a method of and meansfor preventing the cooling and hardening of the major mass of thecasting from affecting the smaller portion or portions of the castingthat have already substantially cooled and hardened.

A still further object of my invention is to provide a method ofmaintaining the molten material entrance passageway clear for thesubsequent entrance flow of the material for producing additionalcastings.

Still further objects of this invention are to provide a means forproducing articles of high density character that is economical inmanufacture, and durable in use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrange ments, andcombination of the various parts of the device, whereby the objectscontemplated are attained as hereinafter more fully set forth,specifically pointed out in my claims, and illustrated in theaccompanying drawing, in which:

FIG. 1 is a vertical side sectional view of my equipment for formingarticles from molten materials, and

FIG. 2 is a horizontal cross-sectional view of the device taken on line2-2 of FIG. 1 and more fully illustrates its construction.

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In the drawing I have used the numeral 10 to designate one side of amold block. The second mold block is generally designated by the numeral11. These two blocks are separable for the purpose of discharging thesolidified casting but are detachably held together 'by any suitablemeans during the actual casting phase. The adacent faces of the blocksare cut away to provide, when the blocks are secured together, the moldcavity 12. Communicating with the mold cavity is a conduit 13 adapted tobe in communication with a suction producmg means (not shown). Imposedin the conduit 13 is a shutoff valve 15. Such structure thus fardescribed 18 standard. The valve 15 is opened and a minus atmosphericpressure is caused to exist within the mold cavity after which themolten material is passed into the mold cavlty. The valve 15 is thenclosed. It is to such equipment that the invention is applied and whichwill now be described in detail.

In the block 11 is formed a relatively large vertical cylinder orpassageway 16 communicating with and formmg a part of the mold cavity asshown in FIG. 1. Slidably mounted in this cylindrical portion 16 is avertical piston ram 17 having its top surface forming at least a portionof the under side of the mold cavity 12. This member 1 7 may be powerreciprocated by any suitable means. Shown in the drawings are a poweredcrank shaft 19 and a connecting rod 20 having one end rotatably mountedon the crank arm 19 and its other end hingedly secured to the bottom ofthe member 17. By this arrangement of parts at least a part of one sideor face of the mold cavity will be movable. The numeral 21 designatesthe molten material inlet conduit communicating with the inside of thecylinder 16 at a point between the extreme movement of the piston member17 in both directions. Therefore, when the piston member 17 is in alowered position the conduit 21 will communicate directly -with theinside of the cylinder 16 but when the piston 17 is elevated in itssliding movement, the point of communication between the conduit 21 andthe cylinder 16 will be closed by the side Wall of the member 17. Thenumeral 22 designates a container having the molten material 23, andinto which the conduit 21 extends. The numeral 25 designates ahorizontal cylinder formed by the two molds and communicating at itsforward end with the mold cavity. The numeral 26 designates a hydraulicpower cylinder having the two conduits 27 and 28 communicating with theinside of its two ends, respectively. These two conduits are adapted tobe controllable adjustable comunication with a source of hydraulicpressure (not shown) or selectively individually denied hydraulicpressure. The numeral 29 designates the piston slidably mounted in thecylinder 250. The numeral 30 designates the piston in the hydrauliccylinder 26. The piston 29 and the piston 3d are secured together by ashaft 31. The practical operation of the device is as follows:

With the two mold sections 10 and 11 closed together and with the pistonram 17 held in a lowered position, the valve 15 is opened therebyproducing a semi-vacuum within the mold cavity. At this time the piston29 is being held to the right in its sliding movement by hydraulicpressure in the forward end of the cylinder 26. Due to the minusatmospheric pressure within the mold cavity and the upper end of thecylinder 16, the molten material 22 will flow into the upper end of thecylinder 16 and mold cavity. After a suitable amount of the moltenmaterial has entered the mold the valve 15 is closed and the piston ram17 is moved upwardly to its maximum elevated position within thecylinder 16 as shown by broken lines in FIG. 1. Next the piston 29 iscaused to move toward the mold cavity under pressure by releasingpressure in the conduit 27 and inducing pressure in the conduit 28, andthis pressure by virtue of the piston 29 Will continue on the moltenmaterial until the molten material has solidified. After the pressurizedcasting has cooled, the two mold halves are separated and the castingtaken therefrom. The vacuum conduit and the conduit should be at theparting line of the two mold portions as shown in the drawing. If theconduit 13 is extended around to indirectly communicate with the moldcavity through the cylinder 25, the piston 29, will, when movedforwardly, cut off the conduit from the interior of the mold cavity.Obvously different castings and different molten materials will requiredifferent treatment and with this apparatus such necessary adjustmentsare easily obtained. As an illustration, the ram piston 17 may be movedupwardly and held under a force of two ton while the pressure on thepiston 29 may be of five ton. Therefore, by increasing or decreasing therelative compressing forces of the two pistons 17 and 29 different typesof castings may be obtained even though the molten material be the same.Also it will be found that some molten materials will require differentrelative pressures than that of other molten materials. Regardless,however, of the pressures and/or the molten materials used, the finishedcasting will have been hot liquid form forged. This forging isaccomplished by initial and continuing pressure on the molten materialuntil it has solidified and cooled. The first stage in the compressingof the molten material is caused by the initial upward movement of thepiston ram 17 which also automatically closes the molten metal inletconduit. As the upper end of the piston ram 17 forms at least a part ofone face of the mold cavity its upward sliding movement must be limitedand this can be accomplished by any suitable means such as shown by thecrank assembly as shown in FIG. 1. After the piston ram 17 has reachedits maximum height, it is held in such position until the casting hasbeen formed. Inasmuch as the member 17 is a movable side of the cavitywall and held in a fixed position during the solidifying of the casting,it is obvious that different shaped castings would require differentelevated positions of the member 17 and this is accomplished by usingdifferent length pistons 17.

From the foregoing it will be appreciated that I have provided a methodof producing articles, by first having a mold wherein one side of themold cavity is movable, the creating of a minus pressure within the moldcavity to draw in thereto the molten material, the compressing of themolten material first by the moving of the part that forms a portion ofthe side of the mold cavity and by an auxiliary controllable pressure onthe molten material within the mold cavity until it has solidified. Itwill also be appreciated that by my construction and arrangement ofparts I have made possible successful vertical casting. By the upwardmovement of the member '17 is will insure the entire successful fillingof the mold cavity with the molten material.

The piston 29 may be synchronized to move inwardly towards the moldcavity 12 at the appropriate time to close the evaluation conduit 13from communication with the m-old cavity 12 and thereby prevent theconduit '13 from being filled with molten metal. At the same time thepiston serves to exert pressure at the most vital area of the die cavity12, its horizontal mid section which is in a plane normal to the line oftravel of the piston ram 17. Only by exerting pressure at this point canthe desired casting be produced.

Some changes may be made in the construction and arrangement of bymethod of and means for producing dense articles from molten materialswithout departing from the real spirit and purpose of my invention, andit is my intention to cover by my claims, any modified forms ofstructure or use of mechanical equivalents which may be reasonablyincluded within their scope.

I claim:

1. In a vacuum die casting machine, comprising a pair of mold sectionswith adjacent facing surfaces, each of said surfaces having a recessformed therein, cooperating to form a mold cavity disposed on a planeextending parallel to said surfaces, said surfaces each having anarcuate recess formed therein and extending around said die cavity andcooperating to form a conduit, said surfaces each having half of acylinder formed therein and cooperating to form a full cylinder, saidconduit opening into said cylinder, a piston disposed in said cylinderand movable to an inward position to close said conduit, a vacuum sourcein communication with said conduit, and said conduit being incommunication with said mold cavity when said piston is in a retractedposition exposing said conduit opening to said cylinder, a hydrau licpower means connected to said piston for selectively moving said pistonbetween said inward position and said retracted position, one of saidmold sections having an enlarge opening formed therethrough in directalignment with said mold cavity, a shot cylinder in communication withsaid enlarged opening and disposed at degrees to said first mentionedcylinder, a ram piston in said shot cylinder, power means forrecipr-ocating said ram piston to a position closely adjacent said moldcavity to a position remote therefrom, a conduit in communication at oneend with the interior of said shot cylinder, a container having moltenmaterial and the other end of said last mentioned conduit incommunication with said molten material.

I 2. The structure of claim 1 wherein said piston in said full cylinderhas a piston rod connected to its outer ends and extends into ahydraulic cylinder included in said hydraulic power means, a hydraulicpiston in said hydrauilic cylinder, a hydrualic conduit in communicationwith said hydraulic cylinder at opposite ends thereof on opposite sidesof said hydraulic piston, said hydraulic power means adapted toselectively force fluid into said hydraulic cylinder on either side ofsaid hydraulic piston whereby said first mentioned piston is movedbetween said inward position and said retracted position.

References Cited by the Examiner UNITED STATES PATENTS 2,181,157 11/1939Smith 22-68 2,781,547 2/1957 Moxness 18-30 2,866,240 12/ 1958 Schroeder22-68 2,890,491 6/1959 Hendry 18-30 2,971,230 2/1961 Coleman et al 22-682,985,928 5/1961 Heskett 22-73 3,070,857 l/1963 Venus 22-73 FOREIGNPATENTS 450,645 8/ 1948 Canada.

WILLIAM J. STEPHENSON, Primary Examiner.

R. A. SANDLER, Assistant Examiner.

1. IN A VACUUM DIE CASTING MACHINE, COMPRISING A PAIR OF MOLD SECTIONSWITH ADJACENT FACING SURFACES, EACH OF SAID SURFACES HAVING A RECESSFORMED THEREIN, COOPERATINH TO FORM A MOLD CAVITY DISPOSED ON A PLANEEXTENDING PARALLEL TO SAID SURFACES, SAID SURFACES EACH HAVING ANARCUATE RECESS FORMED THEREIN AND EXTENDING AROUND SAID DIE CAVITY ANDCOOPERATING TO FORM A CONDUIT, SAID SURFACES EACH HAVING HALF OF ACYLINDER, SAID CONDDIT OPENING COOPERATING TO FORM A FULL CYLINDER, SAIDCONDUIT OPENING INTO SAID CYLINDER, A PISTON DISPOSED IN SAID CYLINDERAND MOVABLE TO AN INWARD POSITION TO CLOSE SAID CONDUIT, A VACUUM SOURCEIN COMMUNICATION WITH SAID CONDUIT AND SAID CONDUIT BEING INCOMMUNICATION WITH SAID MOLD CAVITY WHEN SAID PISTON IS IN A RETRACTEDPOSTION EXPOSING SAID CONDUIT OPENING TO SAID CYLINDER, A HYDRAULLICPOWER MEANS CONNECTED TO SAID PISTON FOR SELECTIVELY MOVING SAID PISTONSBETWEEN SAID MOLD SECTIONS HAVING AN RETRACTED POSITION, ONE OF SAIDMOLD SECTIONS HAVING AN ENLARGE OPENING FORMED THERETHROUGH IN DIRECTALIGNMENT WITH SAID MOLD CAVITY, A SHOT CYLINDER IN COMMUNICATION WITHSAID ENLARGED OPENING AND DISPOSED AT 90 DEGREES TO SAID FIRST MENTIONEDCYLINDER, A RAM PISTON IN SAID SHOT CYLINDER, POWER MEANS FORRECIPROCATING SAID RAM PISTON TO A POSITION CLOSELY ADJACENT SAID MOLDCAVITY TO A POSITION REMOTE THEREFROM, A CONDUIT IN COMMUNICATION AT ONEEND WITH THE INTERIOR OF SAID SHOT CYLINDER, A CONTAINER HAVING MOLTENMATERIAL AND THE OTHER END OF SAID LAST MENTIONED CONDUIT INCOMMUNICATION WITH SAID MOLTEN MATERIAL.